The Nobel Assembly at Karolinska Institutet awarded the 2026 Nobel Prize in Physiology or Medicine jointly to Karl Deisseroth of Stanford University and the Howard Hughes Medical Institute, Peter Hegemann of Humboldt University of Berlin, and Georg Nagel of the University of Würzburg “for their discoveries concerning light-gated ion channels and optogenetics.”
The prize recognizes the development of optogenetics, a method that allows researchers to observe how nerve cells shape memories, feelings, and behaviors in the living brain. According to the Nobel announcement, this breakthrough emerged from Hegemann’s curiosity about how single-celled algae navigate toward light sources.
In the early 2000s, Hegemann and Nagel discovered channelrhodopsin, a protein found in Chlamydomonas algae with unique light-sensitive properties. When illuminated by blue light, the protein creates a channel that allows charged ions to flow into cells, generating electrical impulses. The researchers found that placing the protein in any cell type rendered those cells light-sensitive.
Deisseroth built on this discovery by introducing the channelrhodopsin gene into rat nerve cells. By shining blue light on these cells, he triggered nerve signals—a breakthrough published in 2005. Two years later, he successfully applied this light-controlled switch in the brains of living mice.
The method, now called optogenetics, has achieved rapid global adoption in neuroscience research. Researchers have used it to identify neural circuits governing specific memories, feelings, and behaviors relevant to neurological and psychiatric disorders. According to the press release, clinical researchers are also exploring optogenetics to restore sight in people with visual impairment.
Per Svenningsson, Chair of the Nobel Committee for Physiology or Medicine, stated: “Optogenetics provides opportunities for mapping the brain in a way that we could once only dream of.” Previously, 20th-century brain research could only identify which areas affected which functions but could not establish causal relationships, leaving the understanding of how the brain governs feelings and bodily functions largely mysterious.
The three laureates will share 12 million Swedish kronor equally. The prize recognizes how optogenetics has fundamentally altered understanding of the brain and continues generating new discoveries about how the brain functions.
Key facts
- Karl Deisseroth, Peter Hegemann, and Georg Nagel jointly awarded the 2026 Nobel Prize in Physiology or Medicine
- Hegemann and Nagel discovered channelrhodopsin protein in single-celled algae Chlamydomonas in the early 2000s
- Deisseroth introduced the channelrhodopsin gene into nerve cells and published breakthrough results in 2005
- Successfully applied light-controlled nerve cell switching in living mouse brains in 2007
- Optogenetics enables researchers to map neural circuits controlling specific memories, feelings, and behaviors
- Method being explored to restore sight in people with visual impairment
- Prize amount: 12 million Swedish kronor shared equally among three laureates